I think Jess pretty much nailed it. To do the mopar small block swap, you’ll need a marine bell housing for that engine (fairly rare), or fab something yourself. The thing to be wary of here is that the axles and U-joints of the early Cortezes aren’t really designed to handle the weight and torque of the V8. There are quite a few out there who have done it, but I’ve also heard from members who say they’ve had some issues (overheating too). I personally think that the best solution is to build a stroker slant six. Doug Dutra has talked about his builds this way on slantsix.org. There are also members there who have added turbos and fuel injection to their slants.
